Quick question, I have a 2000 XJ and wanted to be sure which 4WD system I have and that I understand how it works. I'm guressing I have command trac since I don't have the "full time" 4WD setting. In "part time" 4wd, both of my diferentials lock giving me 4 wheel spin? I shouldn't leave it in this mode since it's hard on the running gear...Selec trac when placed in 4H has a limited slip differential so it can be driven in 4WD without the above concern?
thanks!

 

On your 4x4 shifter, what does it say?

2HI-4HI-N-4LO that's is only part time, only use 4x4 on wet surfaces.

 

If you do not have the "full time" option, then you have the NP231 Command-trac. The 4wd options for this are not suitable for dry pavement. In 4HI, it will not lock your differentials.